Controversies in Hypertension I: The Optimal Assessment of Blood Pressure Load and Implications for Treatment

Assessing the relationship between lipoprotein(a) levels and blood pressure among hypertensive patients beyond conventional measures. An observational study

High lipoprotein(a) (Lp(a)) levels are associated with an increased risk of arterial hypertension (AHT) and atherosclerotic cardiovascular disease. However, little is known about the detailed profile of AHT based on Lp(a) levels. This observational study focused on elucidating the relationship between Lp(a) concentrations and specific indices obtained from 24-h ambulatory blood pressure (BP) monitoring in hypertensive patients over 18 years of age. We gathered and analyzed data on BP indices along with demographic, epidemiological, clinical, and laboratory variables from 227 hypertensive patients, median age 56 years, including 127 women (56%). After comparing hypertensive patients with Lp(a) levels above and below 125 nmol/L, we found that a 10 mmHg increase in nocturnal systolic BP and all pulse pressure indices (24-h, daytime, and night-time) was associated with an increased risk of high Lp(a) levels by more than 20% and 40%, respectively. Similarly, each 10% increase in the area under the function over time of nocturnal diastolic BP dipping was associated with more than a 30% decrease in the odds of belonging to the elevated Lp(a) levels category. Additionally, Lp(a) levels above 125 nmol/L were associated with higher 24-h, daytime, and night-time systolic BP and pulse pressure load. The relationship between Lp(a) and AHT appears to extend beyond conventional BP measurements, which may be relevant given the prognostic implications of nocturnal BP and pulse pressure indices.

The effects of obstructive sleep apnea on blood pressure variability and load in patients with hypertension

BACKGROUND

Hypertension frequently coexists with obstructive sleep apnea (OSA), and their interplay substantially impacts the prognosis of affected individuals. Investigating the influence of OSA on blood pressure variability (BPV) and blood pressure load (BPL) in hypertensive patients has become a focal point of clinical research.

METHODS

This cross-sectional study recruited hypertensive patients (n = 265) without discrimination and classified them into four groups based on their apnea-hypopnea index (AHI): control group (n = 40), AHI < 5; mild group (n = 74), 5 ≤ AHI ≤ 15; moderate group (n = 68), 15 < AHI ≤ 30; severe group (n = 83), AHI > 30. All participants underwent comprehensive assessments, including polysomnography (PSG) monitoring, 24-h ambulatory blood pressure (ABP) monitoring, cardiac Doppler ultrasound, and additional examinations when indicated.

RESULTS

BPV and BPL exhibited significant elevations in the moderate and severe OSA groups compared to the control and mild OSA groups (P < 0.05). Moreover, interventricular septum thickness and left ventricular end-diastolic volume (LVEDV) demonstrated higher values in the moderate and severe OSA groups (P < 0.05). Multiple stepwise regression analysis identified noteworthy risk factors for elevated BPV in hypertensive patients with OSA, including AHI, maximum apnea time, total times of oxygen reduction, and mean time of apnea.

CONCLUSION

Hypertensive patients with moderate to severe OSA exhibited substantially increased BPV and BPL. Moreover, BPV was correlated with AHI, maximum apnea time, total times of oxygen reduction, and mean time of apnea in hypertensive patients with OSA.

Controversies in Hypertension III: Dipping, Nocturnal Hypertension, and the Morning Surge

A comprehensive approach to hypertension requires out-of-office determinations by home and/or ambulatory monitoring. The 4 phenotypes comparing office and out-of-office pressures in treated and untreated patients include normotension, hypertension, white-coat phenomena, and masked phenomena. Components of out-of-office pressure may be equally as important as mean values. Nighttime pressures are normally 10 - 20% lower than daytime (normal "dipping"). Abnormalities include dipping more than 20% (extreme dippers), less than 10 % (non-dippers), or rising above daytime (risers) and have been associated with elevated cardiovascular risk. Nighttime pressure may be elevated (nocturnal hypertension) in isolation or together with daytime hypertension. Isolated nocturnal hypertension theoretically changes white-coat hypertension to true hypertension and normotension to masked hypertension. Pressure normally peaks in the morning hours ("morning surge") when cardiovascular events are most common. Morning hypertension may result from residual nocturnal hypertension or an exaggerated surge and has been associated with enhanced cardiovascular risk, especially in Asian populations. Randomized trials are needed to determine whether altering therapy based solely on either abnormal dipping, isolated nocturnal hypertension, and/or an abnormal surge is justified.